or, if you've known them long enough that you should know their last name, ask for their middle name. I went from k-12 with the same people and didnt learn half of their middle names until senior year. Like, one of my best friend's name was Michael. Had no idea his middle name was James until I had to write a speech for the graduating ceremony.

It's in the caustic caverns, if you follow the train tracks to the end (where the cart you need to push is), and look to the right of the tracks, there will be squared terrain, follow it and you should be able to see it almost straight away. There is also a dark souls easter egg, which can be found on the island in the middle of the acid lake near Blue